Excerpts of Chief Cabinet Secretary Yukio Edano's statement, followed by a question-and-answer session, on the unfolding nuclear crisis at a Tuesday morning news conference held around 11 a.m.:
Excerpts of Chief Cabinet Secretary Yukio Edano's statement, followed by a question-and-answer session, on the unfolding nuclear crisis at a Tuesday morning news conference held around 11 a.m.:
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A fire has broken out at the No. 4 reactor (of the No. 1 Fukushima nuclear power plant).
This reactor was not operating when the earthquake struck. While there are no fuel rods in that reactor, there are spent fuel rods stored in the reactor. The heat from the spent fuel rods produced hydrogen that led to a so-called hydrogen explosion.
We speculate that the explosion that occurred was similar to what happened at the No. 1 reactor and the No. 3 reactor.
Hydrogen is being released and it is believed that radioactive materials have also been emitted since the fire. But, because the building no longer fully covers the entire reactor, we have a situation in which (radioactive materials) have been emitted into the air.
We want to solve this situation by extinguishing the fire as soon as possible and then to begin cooling the spent nuclear fuel rods.
There was another incident at the No. 2 reactor, where a blast was heard.
If I recall, the sound occurred at about 6:30 a.m., roughly 30 minutes after (the fire at the No. 4 reactor), but because a hole was created on top of the No. 2 reactor, there is a very low possibility of a large hydrogen explosion occurring there.
However, we believe that there may have been some damage to part of the pressure portion as a result of a small hydrogen explosion or some other type of explosion.
We have received a report of smoke being seen from the No. 2 reactor, but we believe that it is simply steam being emitted from the part that has been damaged.
Work is currently continuing to pump in sea water to the No. 1, No. 2 and No. 3 reactors. The water pumping process is now proceeding smoothly at all three reactors, so we believe that the reactors are being successfully cooled. What we have to do right now is to maintain the cooling, as well as deal with the No. 4 reactor.
Concerning the concentration of radioactive materials, monitors at 10.22 a.m. showed figures of 30 millisieverts in the area between the No. 2 and No. 3 reactors, of 400 millisieverts near the No. 3 reactor and of 100 millisieverts near the No. 4 reactor. Millisieverts are a different unit of measurement from the microsieverts we have been using in previous statements.
Unlike the past unit that we had used, these figures show levels that could potentially affect human health.
Of the 800 employees who were near the affected area at about 6 a.m., 50 workers directly involved in the water pumping process remained and everyone else was evacuated.
Up until the time of this news conference, I received a report that the water pumping process was continuing.
To prepare for such a situation, we had asked that people evacuate from an area within a 20-kilometer radius. In order to further prepare for any eventuality, as the prime minister just said, we are asking people living in a area within a 20 to 30 kilometers radius to remain indoors and to not go outside.
At this time, I want everyone to shut the windows and make their houses as airtight as possible. Please do not use ventilation. We want people to hang their laundry indoors. The farther away one is the lower is the concentration of the radioactive materials.
It is believed that beyond 20 kilometers the concentration is reduced considerably and the effect on human health either becomes much smaller or disappears altogether.
However, to prepare for any eventuality and because these matters are influenced by weather conditions, we are asking those people living within the affected area to remain indoors and not come into contact with the outside air.
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Question: What are the effects to the surrounding area?
Answer: The water pumping process continuing at the No. 1, No. 2 and No. 3 reactors has pumped in a certain amount of water, we believe. We have also received a report that pressure is being maintained within a certain range. We are making efforts to maintain this state of affairs.
Q: Is the fire at the No. 4 reactor more serious than the situation at the No. 2 reactor?
A: We received a report that the incident at the No. 4 reactor occurred first and that was my understanding of the situation, so that is why I spoke about the No. 4 reactor first, before the No. 2 reactor.
Q: Has there been damage to the core containment vessel at the No. 2 reactor?
A: A report said that there was a high probability that damage was incurred.
Q: Is there no mistake that radioactive materials were leaked?
A: As I have said before, radioactive materials at a level that would have little effect on human health has been emitted from the No. 1, No. 2 and No. 3 reactors.
Q: Will the fire at the No. 4 reactor have an effect on the burning of the spent fuel rods?
A: As in other nuclear power plants, (the spent fuel rods) emit heat and as a result it might be possible that radioactive materials could be emitted. It is not the case that the fire would ignite the fuel rods. We are looking to quickly extinguish the fire and cool (the spent fuel rods).
Q: What is the causal relationship between the concentration of radioactive materials around the No. 2, No. 3 and No. 4 reactors and the damage to the containment vessel of the No. 2 reactor?
A: While we cannot say with certainty, we are analyzing the situation as one in which the high level of radioactive materials was due to the explosion at the No. 4 reactor. Although the No. 2 reactor is not currently as stable as the No. 1 and No. 3 reactors, the water pumping has produced a certain result. Although a blast was heard, there was no major change in the levels in the surrounding areas when it occurred, so I received an analysis report that suggested it was due to the explosion at the No. 4 reactor.
Q: What situation do you expect to arise if the fire at the No. 4 reactor should continue?
A: We are making every effort to extinguish the fire. I will be repeating myself, but fundamentally, the fire is not spreading to the spent nuclear fuel rods as one would normally expect of a fire, so the fire will be extinguished once the ordinary parts of the building have completely burned out. The sooner that happens the better. It would not be a good situation for the spent fuel rods to have temperatures rising, so we are making efforts to prevent that.
Q: Is there a possibility that radioactive materials could be released to the outside air due to damage to the containment vessel of the No. 2 reactor?
A: While we believe it is very plausible that a certain amount is being emitted due to the damage, we think the high figures we have now are due to the effects from the No. 4 reactor (fire). Conversely, we feel the effects from and changes at the No. 2 reactor have not contributed greatly.
Q: At yesterday's news conference, you mentioned something about the detection of neutron rays. Is there a possibility of again reaching a critical stage?
A: Due to the characteristics of the No. 3 reactor, my understanding is that it would be possible for neutrons to be emitted from there.
Q: Will there be any problems with that?
A: Of course, it would be better if no neutrons were emitted, but my understanding is that the report said only minor amounts were detected.
Q: How long do you think it will take to extinguish the fire at the No. 4 reactor?
A: We are at this time making every effort at the scene to determine how that can be accomplished as quickly as possible.
Q: What happens after the fire is extinguished?
A: Once it is extinguished, we will confirm the situation as well as consider a safe cooling process. Of course, we have already conducted a simulation beforehand.